The primary factor contributing to obesity is a change in lifestyle. With improved living standards and abundant food supply, people have access to higher calorie foods. On the other hand, the development of automation in industrial and agricultural production, along with the popularity of television, telephones, the internet, and computers, has significantly reduced physical activity and energy expenditure. The combination of these factors creates conditions for obesity.
In contrast, during periods of famine and war, there is insufficient food supply and obesity is rare to be seen. Of course, there is also a genetic component to the development of obesity.
Is obesity hereditary?
Research on the heritability of obesity has found that if both parents have normal weight, the incidence of obesity in their children is below 10%. If one parent is obese, the incidence of obesity in their children is around 40-50%. If both parents are obese, the incidence of obesity in their children can reach 80%. Studies have shown that in families with obesity, both parents and siblings are often obese, indicating similar dietary preferences and lifestyle habits. They tend to consume oily and sweet foods, while eating fewer vegetables and engaging in less physical activity. Studies conducted on 800 children who were adopted shortly after birth showed a clear correlation between the body mass index of the children and their biological parents, especially the mother, but not with the adoptive parents. These observations indicate a close relationship between genetics and the occurrence of obesity.
Are all cases of childhood obesity caused by overeating?
Obesity is often misunderstood as being caused by excessive eating and drinking, rather than being a complex disease. Many facts indicate that there are differences in metabolism and energy utilization among individuals with obesity. Some studies have reported that 80% of obese children have excessive energy intake, but most researchers have not been able to confirm such a high incidence rate. Research results have shown that there is a significant variation in energy intake among children of the same age, with the highest and lowest energy intake differing by a factor of two. It is generally observed that obese children who are taller and larger consume more energy than the average for their age group, but there are also some cases where energy intake is lower. It has been confirmed that the basal metabolic rate of individuals with obesity is not different from that of normal individuals, but their energy expenditure during work is higher than that of normal individuals under the same conditions. However, individuals with obesity tend to have lower physical activity levels, resulting in reduced energy expenditure.
Experimental evidence has shown that the postprandial energy expenditure of individuals with obesity is half that of normal individuals, with most of the energy being used for food digestion, absorption, and liver metabolism. In addition, individuals with obesity have reduced responsiveness to cold environments. In summary, there are differences in energy metabolism between individuals with obesity and normal individuals. Their energy expenditure is lower than that of normal individuals, and their metabolic rate increases less than that of normal individuals in cold environments or during exercise. Animal experiments have shown that the timing of food intake has a significant impact on fat storage in the body. Two groups of animals were given the same type and quantity of food, but one group consumed it quickly while the other group was given the food slowly. The first group showed a 50-100% increase in body weight compared to the second group, indicating that consuming a large amount of food in a short period of time can easily lead to fat accumulation and obesity. Similar findings have been observed in humans, where overeating and consuming a large amount of food in a short period of time can lead to obesity. Additionally, dietary habits and food quality also have an impact on obesity. Foods such as sweets, chocolates, and beer are known to contribute to obesity. People who prefer to lie down after meals are also more prone to obesity.
How does food supply affect childhood obesity?
Children who are afraid of medical treatment often make deals with their parents, promising not to cry during injections in exchange for going to a restaurant to eat. Many parents use candy and sweets as rewards to encourage their children to behave, which leads to excessive consumption of such foods. Therefore, the availability of food directly affects obesity. On the other hand, the way food is supplied also affects the incidence of obesity. Television advertising is a clear example of this. The appearance of television advertising has a significant impact on people's eating habits, and these advertisements often pay little attention to nutrition. For example, various fast food, chocolates, and high-sugar health products are frequently promoted. Many television advertisements specifically target children with high-calorie foods and sweets, which can lead to childhood obesity.
